There are three different kinds of bricks; the Lydian, which is in use with us, a foot-and-a-half in length by a foot in breadth; the tetradoron; and the pentadoron; the word “doron” being used by the ancient Greeks to signify the palm[2237]—hence, too, their word “doron” meaning a gift, because it is the hand that gives.—These last two kinds, therefore, are named respectively from their being four and five palms in length, the breadth being the same. The smaller kind is used in Greece for private buildings, the larger for the construction of public edifices. At Pitane,[2238] in Asia, and in the cities of Muxilua and Calentum in Farther Spain, there are bricks[2239] made, which float in water, when dry; the material being a sort of pumice-earth, extremely good for the purpose when it can be made to unite. The Greeks have always preferred walls of brick, except in those cases where they could find silicious stone for the purposes of building: for walls of this nature will last for ever, if they are only built on the perpendicular. Hence it is, that the Greeks have built their public edifices and the palaces of their kings of brick; the wall at Athens, for example, which faces Mount Hymettus; the Temples of Jupiter and Hercules at Patræ,[2240] although the columns and architraves in the interior are of stone; the palace of King Attalus at Tralles; the palace of Crœsus at Sardes, now converted into an asylum[2241] for aged persons; and that of King Mausolus at Halicarnassus; edifices, all of them, still in existence. Muræna and Varro, in their ædileship, had a fine fresco painting, on the plaster of a wall at Lacedæmon, cut away from the bricks, and transported in wooden frames to Rome, for the purpose of adorning the Comitium. Admirable as the work was of itself, it was still more admired after being thus transferred. In Italy also there are walls of brick, at Arretium and Mevania.[2242] At Rome, there are no buildings of this description, because a wall only a foot-and-a-half in thickness would not support more than a single story; and by public ordinance it has been enacted that no partition should exceed that thickness; nor, indeed, does the peculiar construction of our party-walls admit of it. CHAP. 50. (15.)—SULPHUR, AND THE SEVERAL VARIETIES OF IT: FOURTEEN REMEDIES. Let thus much be deemed sufficient on the subject of bricks. Among the other kinds of earth, the one of the most singular nature, perhaps, is sulphur, an agent of great power upon other substances. Sulphur is found in the Æolian Islands, between Sicily and Italy, which are volcanic, as already[2243] stated. But the finest sulphur of all, is that which comes from the Isle of Melos. It is obtained also in Italy, upon the range of hills in the territories of Neapolis and Campania, known as the Leucogæi:[2244] when extracted from the mines there, it is purified by the agency of fire.